Most systems that are designed to gather heat from the rays of the sun include a solar collector, which is the unit which actually receives the sun's rays and converts them to a useful form. Most solar collectors use a flowing medium, such as air or other gas, or a liquid, such as water or some other inexpensive liquid, capable of retaining heat. In some cases, the rays of the sun operate directly on the flowing medium while in others, there are intermediate elements. The use of air has a number of advantages as the flowing medium for transferring heat from the solar collector to the place where it is to be used. Among other things, it does not freeze in the winter and it is readily transferred to one place to another by use of low energy fans and dampers. If handled properly and kept free of moisture, it does not corrode or deteriorate the elements through which it flows. If suffers, however, from a number of disabilities, one of which is its low capacity for absorbing heat. In other words, it takes large amounts of air flow through the solar collector to pick up sufficient heat to be practical. Therefore, there is a tendency in an air solar collector to allow a loss of flow or leakage for the reason that it does not seem to the designer to appreciably reduce the efficiency. In the solar collectors of the past that have used air there has been difficulty in concentrating the sun rays sufficiently to heat the air to a large amount during the limited resident time that it spends in the collector. These and other difficulties experienced with the prior art devices have been obviated in a novel manner by the present invention.
It is, therefore, an outstanding object of the invention to provide a solar collector which is capable of operating effectively either in very cold or very hot weather.
Another object of this invention is the provision of a solar collector making use of air as the flow medium in which leakage has been reduced to practical limits.
It is another object of the instant invention to provide a solar collector which is simple in construction, which is inexpensive to manufacture, and which is capable of a long life of useful service with a minimum of maintenance.
Another object of the invention is the provision of a solar collector, including an air-tight duct construction enclosed within an insulated outer enclosure of less expensive construction.
A still further object of the invention is the provision of a solar collector, using flowing air as the heat absorbent material, in which the elements are arranged to produce the greatest efficiency in transfer of the heat of the sun's rays to the outgoing air.